Marijuana is the most commonly used illicit drug in the United States. However, the treatment options for cannabis dependence are limited; notably, no effective pharmacotherapy has been developed. Conceptually, the ideal medication treatment for cannabis dependence would:

Conceptually, the pharmacodynamic and clinical actions of quetiapine suggest that it may be useful for cannabis dependence. By antagonizing dopamine, quetiapine may interfere with the reinforcing effects of cannabis, while serotonin type 2A, histamine type 1, and adrenergic receptor antagonism may reduce cannabis withdrawal symptoms, primarily by sedating and anxiolytic effects. The proposed research project is an open-label pilot study to evaluate the tolerability and ideal target dosing range for quetiapine treatment of cannabis dependence over an eight-week period. The purpose of this pilot study is to obtain preliminary data regarding the potential efficacy, tolerability and safety of quetiapine treatment of cannabis dependence before conducting a larger double-blind trial.

Eligibility

Ages Eligible for Study:

18 Years to 65 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Between the ages of 18-65

Meets DSM-IV criteria for current cannabis dependence

Seeking treatment for cannabis dependence

Reports using cannabis an average of five days per week over the past 28 days

Capable of giving informed consent and complying with study procedures

Exclusion Criteria:

Lifetime history of DSM-IV diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder

Current DSM-IV criteria for any other psychiatric disorder that may, according to the investigator's judgment, require either pharmacological or non-pharmacological intervention over the course of the study

Receiving prescribed psychotropic medication

Known history of allergy, intolerance, or hypersensitivity to quetiapine

Pregnancy, lactation, or failure to use adequate contraceptive methods in female patients who are currently engaging in sexual activity with men

Unstable medical conditions, such as poorly controlled diabetes or hypertension, which might make participation hazardous

Current DSM-IV diagnosis of substance dependence other than cannabis or nicotine dependence

Are legally mandated to participate in a substance use disorder treatment program

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To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below.
For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00954681